(i) Field of the Invention
The present invention relates generally to models used for representing atoms and molecules, and in particular to a novel and improved model of this type including provision for dynamic representation of molecular and atomic orbitals.
(ii) Description of the Prior Art
Many patents are directed to such molecular models. For example U.S. Pat. No. 2,974,425, patented March 1961, by Dreiding, included a large number of different model building components. Since the components were formed from machined steel they were inflexible and thus models of certain molecules and compounds could not be constructed therefrom. In addition, inasmuch as machined steel was utilized, the overall cost of the set was quite high and could not be afforded by students and the like.
U.S. Pat. No. 3,080,662, patented Mar. 2, 1963, by Bramlik, proposed to provide a chemical model which was capable of representing the volume orbitals and of demonstrating their spatial arrangement and interactions so as to exemplify the important role which they played in chemical reactions. The patentee also proposed to provide a chemical model which was capable of representing the greatest number of molecules, radicals and ions with the smallest number of different piece-types, so as to minimize the cost of a model set of any given size. By means of his inventive concept, the patentee proposed to provide a model assembly for representing the atomic and molecular orbital structure of atoms in a molecule. The assembly included at least one body representing the atom core, at least one body shaped to represent the three dimensional character of an atomic orbital, and means for selectively connecting the bodies the depict an atom having at least on unshared electron pair orbital.
Canadian Patent No. 712,758, patented July 6, 1965, by Bramlik, proposed to provide a molecular model assembly which comprised a plurality of coupling units each represented the center and the directed valence orbitals of a single atom. Each had arm sections angularly arranged in accordance with the symmetry axes of valence orbitals and bond angles of the atom to be depicted by the coupling unit. A plurality of elongated cylindrical sections were provided, each being sized for frictional-mounting at each end on respective arm sections of the coupling units. The cylindrical sections were respectively sized to represent accurately to scale the sigma bond distances between bonded atoms represented by the coupling units, and the Van der Waal's radii of unshared electron pair orbitals, pi orbitals and polynuclear pi orbitals. The cylindrical sections were colour-coded respectively to depict atoms of selected elements. The coupling units and cylindrical sections were thus capable of being coupled to form an accurate frame work model of a selected molecule including accurate scale representations of bond angles, bond distances, covalent radii, and Van der Waal's radii.
U.S. Pat. No. 3,230,643, patented January 1966, by Mathus, provided a combination of plastic parts for the atoms and metal tubing for the bonds. This set required the gluing of the plastic parts which comprised the atoms. Since the bonds were represented by metal tubing, the resulting molecular model members were relatively inflexible which resulted in the fracturing of these members across the glue line when the metal tubing was stressed. In addition, because of this inflexibility, the models of a number of different organic molecules and compounds, such as those requiring less than a five member ring, could not be formed.
U.S. Pat. No. 3,333,349, patented Aug. 1, 1967, by Bramlik, provided a large number of different components and utilized tubing to connect such components. Since the user had to cut the tubing for his own needs, it was very possible that incorrect lengths would be cut which would result in the formation of a model of a molecule or compound with an incorrect spatial relationship between the atoms. In this case, dimensional accuracy between atoms would not exist and the resulting molecule or compound may have been impossible of actual existence.
U.S. Pat. No. 3,510,962, patented May 12, 1970, by Sato, attempted to solve two problems. The first problem to be met consisted of how to orient the various bond angles of the model to represent the actual bond angles of the molecules. The second problem resided in the connections between the spherical and polyhedral ball members and the bond members. A tight but rotatable telescopic engagement of these members was required. The patentee provided a molecular structure educational model for use in teaching stereo-chemistry comprising polyhedral block members each having fourteen facets and a cubic configuration with eight corners cut away along the straight lines connecting the centres of the adjacent ones of the twelve edges forming six square facets and eight equilateral triangular facets. Every pair of opposite facets of each polyhedral block member was parallel to each other, and each of the facets had a hole in the center thereof perpendicular to the plane of the facet. Rod members were insertable in the holes to interconnect the polyhedral block members.
Canadian Patent No. 871,230, patented May 18, 1971, by Bramlik, proposed to provide molecular orbital models by means of a model assembly for representing the atomic and molecular orbital structure of atoms in a molecule. The assembly comprised a plurality of units which represented atom cores, each of the units comprised a solid body having the form of a polyhedron with triangular planar faces and with a bore at each corner thereof arranged in accordance with the symmetry axes of the valence orbitals and bond angles of the atom to be depicted by the unit, the bodies of the plurality of atom core units were of three types respectively defining a tetrahedron, a trigonal bipyramid and an octahedron depicting the forms of the hybridization states of a single atom. A plurality of such units represented atomic orbital lobes and each comprises a hollow body of substantially ellipsoid-shape which had a terminal bore. Coupling means were provided in the form of elongated members which had end portions sized for frictional-mounting within the bores of the atom core units and orbital lobe units for interconnecting selected atom core units and for connecting selected orbital lobe units to the atom core units to form semi-skeletal models of selected molecules including scale representations of bond angles, bond distances, atomic orbitals and internuclear distances, with the molecules shown in ground states and excited states.
Canadian Patent No. 907,320, patented Aug. 15, 1972, by Forsstrom, attempted to provide a construction series for molecular models which comprised, in combination, a first unit in the form of a spherical segment which had a spherical surface of a size substantially greater than a semi-sphere, and which had a flat surface formed with a recess on the flat surface for receiving a portion of a spherical surface of another unit. An interengageable member, extended from the bottom of the recess centrally of the recess and approximately to the flat surface. The spherical surface of the first unit was formed with at least one aperture which had a cross-section corresponding to that of the cross-section of the interengageable member. Two units could thus be joined by inserting the interengageable member of the first unit into an aperture of the other unit.
Canadian patent No. 949,311, patented June 18, 1974, by Nicholson, proposed to provide a model representing a molecular structure which comprised atoms and interatomic bonds. A unit, which represented a multivalent, atom comprised a spherical body which had a single socket which comprised a cylindrical hole of circular cross-section diametrically-extending of the body with a depth greater than the radius of the body and a plurality of integral arms radiating from the body. Each of the atoms had a portion of polygonal cross-section at the sphere and the number of arms was one less than the valence number of the atom represented. The socket and the arms were oriented relative to one another at substantially the correct valency angles of the atom, each arm had, at its free end, a cylindrical portion of a diameter tightly to fit into a like socket of another unit of the model and a length at least as great as the depth of the socket. In this way, a plurality of units were assembled with an integral arm of one unit fitting into the socket of another unit without play to form a substantially-rigid structure.
U.S. Pat. No. 4,020,656, patented May 3, 1977, by Dreiding, proposed to provide a set of structural elements for forming stereo-chemical models of molecular bonds between polyvalent atoms. Each structural element had at least two connector arms representing the valences of at least one atom. Each of the connector arms had opposite inner and outer and portions and were coupled at its inner end portion with a corresponding end portion of at least one other of the connector arms of the same structural element. The outer of each connector arm comprised manually-operably means for pair-wise equiaxial coupling and uncoupling the arm to or from a corresponding outer end portion of another connector arm of the same structural element or of another one of the structural elements. The means for pair-wise coupling and uncoupling the outer end portions of the connector arms comprised identically-designed coupling devices at each outer end portion of all connector arms. The coupling devices were configured for direct coupling of any two outer end portion of all connector arms without auxiliary means, the connector arms each comprised a flexible element which was normally rectilinear when unloaded.
Canadian Patent No. 1,147,143, patented May 31, 1983, by LeBlanc, attempted to provide a model assembly which comprised two spaced spheres which represented carbon atoms. Each sphere carried a fixed blade extending toward the other sphere with the fixed blades representing a hybridized "sp.sup.2 " orbital, and each sphere carried a blade representing an unhydbridized "p"" orbital movable in a first plane toward the other sphere to at least partially overlap or contact the corresponding blade carried by the other sphere which had been moved toward the first sphere in the first plane. Each sphere carried a pair of blades which each represented hybridized "sp.sup.2 " oribtals and which were simultaneously-movable in a second plane which was normal to the first plane. In each sphere the inner end of the blade which represented the hybridized "p" orbital was interconnected with the inner ends of the blades movable in the second plane which represented hybridized "sp.sup.2 " orbitals whereby movement of the unhybridized "p" orbital blade towards the other sphere resulted in simultaneous movement of the related pair of hybridized "sp.sup.2 " orbitals away from the other sphere to a position in the second plane where the three hybridized "sp.sup.2 " blades were separated by 120.degree..
U.S. Pat. No. 4,398,888, patented Aug. 16, 1983, by Darling et al., proposed to provide a molecular model building member which comprised a first end portion, a second end portion, and two arms connecting the first end portion and the second end portion, each of the two arms were substantially-symmetrical about its axis. The first end portion and the second end portion each had an opening formed therein to receive another molecular model building member to form a model of a molecule. Each of the first and second end portions had a projection formed thereon oppositely-directed from the opening formed therein. The opening was provided with inwardly-extending lips of the entrance thereto for engagement with the projection provided on another molecular model building member to interlock with the other molecular model building member when received within the opening adjacent the inwardly-extending lips.
Canadian Patent No. 1,179,497, patented Dec. 18, 1984, by Barrett, proposed to provide an interlocking molecular model system which comprised: a first component representative of an atom and which included at least one elongated shank outwardly-extending from a part of the component which represented the nucleus of the atom. The shank had a first cylindrical section of one cross-sectional area at its outer end, a second cylindrical section of smaller cross-sectional area adjacent the end of the first cylindrical section which faced the part of the component which represented the nucleus, the surface of the shank between the first and second cylindrical sections defined a shoulder inwardly-extending from the surface of the first cylindrical section, and an abutment extending transversely-outwardly relative to the axial direction of the second cylindrical section and adjacent to the end of the second cylindrical section closer to the part of the component which represented the nucleus. A fastener component was provided which comprised a hollow tubular position longitudinally-slotted at one end and had an axial length representative of a predetermined portion of a covalent radius of the atom, the inner surface at one end of the slotted end portion comprised an inwardly-extending axial lock which fit over the second cylindrical section of the first component to be hooked behind the shoulder on the shank and had an axial length substantially equal to the axial length of the second cylindrical section. The fastener component could thus be axially-interlocked with the shank so that the distance between the part of the first component which represented the nucleus and the remote end of the tubular portion of the fastener component was representative of the covalent radius of that atom, and the inner surface of the part of the tubular position between the axial lock and the remote end had a cross-sectional area large enough to fit over the first cylindrical section.
U.S. Pat. No. 4,325,698, patented Apr. 28, 1987, by Darling et al., and its corresponding Canadian Patent No. 1,167,637, patented May 22, 1984, proposed to provide a molecular model building member which comprised a main portion with two arms connected to and emanating outwardly from the main portion. The member was formed of relatively flexible material which permitted the arms to be bendable relative to the main portion. One of the arms was comprised of a first section connected to the main portion and a second section connected to the first section so that the first section was interposed between the main portion and the second section. The second section of one of the arms had an annular rib around the periphery thereof and had a smaller cross-section than the first section so as to form a first annular shoulder at their intersection. The other of the arms had a bore therein to receive the second section of the one of the arms of another of the molecular model building members and to frictionally-engage the annular rib provided thereon.